A friend of Sargeant said Jones’ treatment of his former minister had been “unforgivable” and he should “do the right thing and resign”.

A spokesman for the First Minister said: “This is a difficult time for everybody, particularly Carl’s family, who are still coming to terms with this horrific news.

“Like everyone in the Welsh Labour family Carwyn is deeply upset by the death of his friend.”

Welsh Labour AMs will gather in the assembly to “remember Carl and discuss the tragic events of the past week” and Jones will make a statement after the meeting.

PA Wire/PA ImagesThe death of Carl Sargeant has left his family devastated.

Bernie Attridge, the deputy leader of Flintshire council and a councillor in Sargeant’s home town Connah’s Quay demanded the First Minister’s resignation.

“My mourning is turning into anger in the way my friend was treated by so-called people who say they were his friend,” he said.

In a message to Mr Jones he added: “I call on you to do the right thing and resign. The way you have treated Carl is unforgivable, you make me sick.”

Attridge is not the only Labour politician to have raised concerns about the situation.

Labour AM Jenny Rathbone said: “It is a basic fairness that you have got to know what the accusations are against you in order to be able to respond but that doesn’t mean to say we don’t need to take allegations seriously, we obviously do.”

Labour’s women and equalities spokeswoman Dawn Butler initially issued a call for an investigation into how Welsh Labour handled the case, telling BBC Radio 5 Live that “it doesn’t sound as though everything that should have happened, happened”.

Rhondda MP and former minister Chris Bryant said: “If this fortnight teaches anything it is there must be a fair and proper process for those who feel they have been harassed or abused and fair due process for those facing allegations.

Sargeant’s family published correspondence between his solicitor and the Labour Party about the case.

In a letter and email sent to the Labour Party on Monday, Mr Sargeant’s solicitor Huw Bowden made clear that the Alyn and Deeside AM “categorically denied” any wrongdoing and appealed to the party to provide details of the accusations against him.

He noted the party had confirmed that no “parallel investigations” - such as a police inquiry - were being conducted.

Writing the day before the 49-year-old’s death, Mr Bowden warned that the case was causing Sargeant anxiety and distress and that any delays in concluding the party’s investigation would be “prejudicial ... to his physical and mental well-being”.

Bowden also complained that broadcast interviews by Mr Jones, in which the Welsh First Minister said he had been informed of “a number of incidents” relating to Mr Sargeant’s behaviour with women, were prejudicing the inquiry.

A spokesman for the Sargeant family said: “The distress of not being able to defend himself properly against these unspecified allegations meant he was not afforded common courtesy, decency or natural justice.”

EMPICS EntertainmentDeputy Labour leader Tom Watson

Asked what Jones should say in his statement, former first minister Alun Michael told BBC Radio 4′s Today programme: “I hope it will become clearer what the allegations were and why it was that the matter was referred to the Labour Party to deal with.

“I hope that the family will have the response that they are understandably seeking - what were the allegations and why were they not shared with Carl, as the person who was under criticism, and why was the support not given and who should have given it?

“The problem for everybody - family, friends, people involved in the wider public life in Wales - is that we don’t know what this is all about.”

Labour’s deputy leader Tom Watson declined to comment on the handling of Mr Sargeant’s case, telling the Today programme: “If we do need to learn any lessons about our procedures from this, we will do.

“But I think at a time of maximum grief, when we are all in shock, it is probably not right for me to comment on who said what to whom.”